A U.S. F-15 and a UK police helicopter investigating drone exercise got here inside 1,900 ft of vertical separation throughout a nighttime encounter. No danger of collision was recognized.
A Nationwide Police Air Service (NPAS) helicopter dispatched to research reviews of drone exercise close to RAF Lakenheath final November had a close to miss with what it believed to be an unmanned aerial car, solely to later uncover it was a U.S. F-15E Strike Eagle.
Based on a report revealed by the BBC and authored by Matt Precey, the UK Airprox Board, which investigates airspace security incidents, concluded that the helicopter crew had misidentified the purple flashing lights of a fast-moving F-15 as belonging to a drone.
The incident occurred on the night of Nov. 22, 2024, because the NPAS EC135 helicopter responded to a police request to research a number of drone sightings close to Lakenheath and the encompassing areas.
Because the helicopter entered Lakenheath’s airspace, its crew noticed what they believed had been drones maneuvering close by. Based on the Airprox report, one of many objects “appeared to converge with them and fly above and in entrance of them,” even overtaking the helicopter at one level. The plane got here as shut as 1,900 ft (579 meters) vertically, prompting the helicopter pilot to categorise the danger of collision as ‘medium’.
Right here’s an excerpt from the investigation report:
The EC135 Pilot reviews that that they had flown at 1500ft in direction of Lakenheath ATZ, contacted Lakenheath Radar on 128.900MHz (the EC135 will not be UHF-equipped) and got a clearance into the zone at 1500ft. They weren’t knowledgeable of every other site visitors within the zone and so they didn’t obtain any site visitors returns on their TCAS. They noticed purple flashing lights within the space of the Lakenheath ATZ (which, on the time, they believed had been drones) at a peak in extra of 1500ft. [The pilot of the EC135 reported initially that] the ‘drones’ seemed to be finishing up massive orbits of Lakenheath airfield. They vacated the zone, and had suggested ATC of their intentions to vacate the zone, after which climbed to estimate the peak of the ‘drones’.
After climbing to roughly 4000ft, they began heading east in direction of Bury St Edmunds, monitoring a ‘drone’ which was to the north of them at a barely better altitude. A number of transmissions had been made to ATC to clarify what they had been doing in addition to what the ‘drones’ had been doing. As soon as they began heading in a westerly course (now at 5500ft) one of many ‘drones’ appeared to converge with them and fly above and in entrance of them.
The investigation decided that this was the Closest Level of Strategy (CPA).
By then, they had been conscious that ATC was talking to different callsigns (F15s) and the [F15 callsign] was heard however, on the time, they weren’t conscious that they had been within the zone. There have been nonetheless no returns on their TCAS. A descending flip to the left was carried out to extend their perceived separation from the ‘drone’. [The pilot of the EC135 reported initially that] at one stage that they had a major charge of descent at 145kt and the ‘drone’ overtook them, sustaining a continuing peak above them. Now on a southerly observe, they continued the descent to beneath 2000ft the place it appeared that the ‘drone’ was now not monitoring them. There was two-way communication with the pilot of the [F15] over the last course change, the place [the pilot of the EC135] acknowledged that they thought they had been being shepherded away from the world and they’d return to base. [The pilot of the EC135] cleared with ATC andreturned to base.
The pilot and crew of the EC135 commented that they didn’t observe normal plane lights visually and none had been picked up on the onboard digital camera methods. This may occasionally have strengthened the crew’s notion that that they had noticed a drone.
It was solely after the Airprox Board reviewed all obtainable info, together with flight knowledge and army site visitors logs, that it decided the so-called drone was, actually, a U.S. Air Drive F-15 working underneath regular circumstances out of RAF Lakenheath. The board additionally famous that Lakenheath Strategy Management had not knowledgeable the NPAS crew of the fighter’s presence within the space, a lapse which will have contributed to the confusion.
The F-15 pilot reviews that, round 2200, [they were] general-handling inside an agreed block of SFCFL150 inside 20NM of RAF Lakenheath, with Lakenheath Radar Strategy Management (RAPCON) ‘Overlord’, on UHF. [The pilot of the F15] remained exterior managed airspace. According to normal working process, [they were] working with anti-collision lights, nav lights and formation lights all switched on and so they had been working their transponder with Modes A and C. They had been paying specific consideration to their ranges as a result of proximity of the managed airspace to their working space. In the direction of the top of the sortie, they obtained communications on an Operations frequency {that a} police helicopter was working within the space. They had been initially unable to determine the helicopter utilizing the onboard radar and requested Lakenheath ATC to offer a ‘point-out’ to the helicopter. The Lakenheath controller indicated the helicopter was 12NM vary at 5000ft. After receiving the ‘point-out’, they had been in a position to determine [the EC135] observe utilizing their onboard radar. They had been additionally in a position to make use of different methods to help the crew in sustaining contact with [the EC135]. They then flew in direction of the helicopter while sustaining FL60. At the moment, they requested to alter to the identical frequency because the police helicopter pilot, and so they got a VHF frequency (128.9MHz).
Lakenheath ATC repeatedly issued additional Site visitors Info to [the pilot of the F15] till the helicopter was sighted visually. [The pilot of the F15] was visible with the helicopter of their 10 o’clock at 1NM, 1000ft beneath them. As soon as visible, they utilised onboard sensors to take care of their situational consciousness of the helicopter. They heard radio calls between the police pilot and Lakenheath ATC. They maintained at the least 1000ft above the helicopter while within the neighborhood and adopted behind. [The pilot of the F15] tried 3 instances to name the police pilot on the radio. The police helicopter pilot solely responded on to one among these calls and mentioned one thing just like ‘we’re going to RTB’. [The pilot of the F15] noticed the police helicopter make an aggressive 90-120° flip to the south and descend quickly. They maintained their stage overhead and behind the helicopter. On listening to that the helicopter pilot was returning to base, they turned north to return to Lakenheath.
Due to this fact, whule the F-15 pilot was conscious of the helicopter’s place, the NPAS helicopter crew wasn’t. Investigators advised it might have been useful for Lakenheath ATC to have offered reciprocal site visitors info to the EC-135 to reinforce situational consciousness.
Including to the confusion, the helicopter’s site visitors collision avoidance system didn’t detect the fighter, possible attributable to limitations in TCAS performance at excessive closure charges and altitudes.
NPAS later clarified that the crew had acted professionally based mostly on the data obtainable to them on the time. “Within the absence of any contradictory info, the crew acted on the idea that they had been observing drone operations,” mentioned Chief Superintendent Vicki White, in response to the BBC. “The crew demonstrated professionalism and sound judgement in figuring out a possible hazard.”
The U.S. Air Drive confirmed that the F-15 pilot maintained visible contact with the helicopter and complied totally with UK air site visitors rules. A USAF spokesperson added that controllers offered the agreed providers to pilots of each plane to make sure security of flight operations.
In the long run, the Airprox Board acknowledged that the EC135 pilot had acted in good religion, believing they had been observing drone exercise. The incident occurred at night time, with restricted visible references and no night time imaginative and prescient gear on board, making identification more difficult.
Nonetheless, post-incident evaluation revealed that the article was not a drone however a fast-moving F-15 Eagle working at a better distance and altitude than initially perceived. Radar knowledge confirmed there had been vital vertical separation, and the Board concluded there was no precise danger of collision. The occasion was assigned Danger Class E, indicating that security had not been compromised.
Three contributing elements had been recognized: the EC135 crew was not made conscious of the F-15’s presence by Lakenheath controllers (though not strictly required underneath Fundamental Service), had no situational consciousness of the fighters, and misidentified the quick jet as a drone attributable to its lights and trajectory.
You will need to spotlight that the shut encounter occurred throughout a interval of heightened sensitivity, as a number of alleged drone sightings had been reported over three separate army airfields within the area. These sightings are nonetheless underneath investigation by the Ministry of Defence Police.
Though the was no precise danger of collision, the incident highlights how, at night time, lights within the sky can usually be misidentified as drones, even by knowledgeable eyes, resulting in confusion.
Not each mild within the sky is a UFO!! The reviews about mysterious drones over U.S. bases have created a type of public hysteria. Persons are sharing movies of so-called “drones” that, “seem like planes”, “sound like planes”, however are clearly simply planes! It’s like they’re…
— David Cenciotti (@cencio4) December 5, 2024
